A HISTORY OF
MEDIAEVAL JEWISH PHILOSOPHY
BY
ISAAC HUSIK, A.M., Ph.D.ASSISTANT PROFESSOR OF PHILOSOPHY IN THE UNIVERSITY
OF PENNSYLVANIA
THE MACMILLAN COMPANY1918
All rights reserved
COPYMGHT, I916
By the MACMILLAN COMPANY
Set up and electrotyped. Published October, 1916.
This book is issued by the Macmillan Company
in conjunction with the Jewish Publication Society
of America.
TO
SOLOMON SOLIS COHEN, M.D.AS A TOKEN
OF
GRATITUDE AND ESTEEM
PREFACE
No excuse is needed for presenting to the English reader a Historyof Mediaeval Jewish Philosophy. The English language, poor enough
in books on Jewish history and literature, can boast of scarcely any-
thing at all in the domain of Jewish Philosophy. The Jewish Ency-
clopedia has no article on Jewish Philosophy, and neither has the
eleventh edition of the Encyclopedia Britannica. Hastings' Encyclo-
pedia of Religion and Ethics will have a brief article on the subject
from the conscientious and able pen of Dr. Henry Malter, but of books
there is none. But while this is due to several causes, chief among
them perhaps being that English speaking people in general and Amer-
icans in particular are more interested in positive facts than in tentative
speculations, in concrete researches than in abstract theorizingthereare ample signs that here too a change is coming, and in many spheres
we are called upon to examine our foundations with a view to making
our superstructure deep and secure as well as broad and comprehen-
sive. And this is nothing else than philosophy. Philosophical studies
are happily on the increase in this country and more than one branch
of literary endeavor is beginning to feel its influence. And with the
increase of books and researches in the history of the Jews is coming
an awakening to the fact that the philosophical and rationalistic move-
ment among the Jews in the middle ages is well worth study, in-
fluential as it was in forming Judaism as a religion and as a theological
and ethical system.
But it is not merely the English language that is still wanting in a
general history of Mediaeval Jewish Philosophy, the German, French
and ItaHan languages are no better off in this regard. For while it is
true that outside of the Hebrew and Arabic sources, German books
and monographs are the sine qua non of the student who wishes to
investigate the philosophical movement in mediaeval Jewry, and the
present writer owes very much to the researches of such men as Joel,
Guttmann, Kaufmann and others, it nevertheless remains true that
there is as yet no complete history of the subject for the student or the
viii PREFACE
general reader. The German writers have done thorough and distin-
guished work in expounding individual thinkers and problems, they
have gathered a complete and detailed bibliography of Jewish philo-
sophical writings in print and in manuscript, they have edited and
translated and annotated the most important philosophical texts.
France has also had an important share in these fundamental under-
takings, but for some reason neither the one nor the other has so far
undertaken to present to the general student and non-technical reader
the results of their researches.
What was omitted by the German, French and English speaking
writers was accomplished by a scholar who wrote in Hebrew. Dr.
S. Bernfeld has written in Hebrew under the title "Daat Elohim"
(The Knowledge of God) a readable sketch of Jewish Religious philos-
ophy from Biblical times down to "Ahad Haam." A German scholar(now in America), Dr. David Neumark of Cincinnati, has undertaken
on a very large scale a History of Jewish Philosophy in the Middle
Ages, of which only a beginning has been made in the two volumes so
far issued.
The present writer at the suggestion of the Publication Committee
of the Jewish Publication Society of America has undertaken to write
a history of mediaeval Jewish rationalistic philosophy in one volume
a history that will appeal alike to the scholar and the intelhgentnon-technical reader. Treating only of the rationalistic school, I
did not include anything that has to do with mysticism or Kabbala.
In my attempt to please the scholar and the layman, I fear I shallhave succeeded in satisfying neither. The professional student will
miss learned notes and quotations of original passages in the language
of their authors. The general reader will often be wearied by the
scholastic tone of the problems as well as of the manner of the discus-
sion and argument. And yet I cannot but feel that it will do both
classes goodthe one to get less, the other more than he wants. Thelatter will find oases in the desert where he can refresh himseK and take
a rest, and the former will find in the notes and bibUography references
to sources and technical articles where more can be had after his own
heart.
There is not much room for originality in a historical and expository
work of this kind, particularly as I believe in writing history objec-
PREFACE IX
tively. I have not attempted to read into the mediaeval thinkers
modern ideas that were foreign to them. I endeavored to interpret
their ideas from their own point of view as determined by their history
and environment and the hterary sources, religious and philosophical,
under the influence of which they came. I based my book on a studyof the original sources where they were availableand this appliesto all the authors treated with the exception of the two Karaites,
Joseph al Basir and Jeshua ben Judah, where I had to content my-
seK with secondary sources and a few fragments of the original texts.
For the rest I tried to tell my story as simply as I knew how, and I hopethe reader will accept the book in the spirit in which it is offeredasan objective and not too critical exposition of Jewish rationalistic
thought in the middle ages.
My task would not be done were I not to express my obligationsto the PubHcation Committee of the Jewish Publication Society of
America to whose encouragement I owe the impulse but for which
the book would not have been written, and whose material assistance
enabled the pubUshers to bring out a book typographically so attrac-
tive.
Isaac Husik.
Philadelphia,
July, igi6.
TABLE OF CONTENTSPAGE
Preface viiIntroduction xiiiCHAPTER
I. Isaac Israeli i
II. David ben Merwan Al Mukammas 17III. Saadia ben Joseph Al-Fayyumi 23IV. Joseph Al-Basir and Jeshua ben Judah 48V. Solomon Ibn Gabirol 59VT. Bahya Ibn Pakuda 80VII. Pseudo-Bahya 106
VIII. Abraham Bar Hiyya 114IX. Joseph Ibn Zaddik 125X. Judah Halevi 150XI. Moses and Abraham Ibn Ezra 184XII. Abraham Ibn Daud 197XIII. Moses Maimonides 236XIV. Hillel ben Samuel 312XV. Levi ben Gerson 328XVI. Aaron ben Elijah of Nicomedia 362XVII. Hasdai ben Abraham Crescas 388XVIII. Joseph Albo 406Conclusion 428Bibliography 433Notes 439List of Biblical and Rabbinic Passages 449Index 451
INTRODUCTION
The philosophical movement in mediaeval Jewry was the result of
the desire and the necessity, felt by the leaders of Jewish thought, of
reconciling two apparently independent sources of truth. In the
middle ages, among Jews as well as among Christians and Moham-
medans, the two sources of knowledge or truth which were clearly
present to the minds of thinking people, each claiming recognition,
were religious opinions as embodied in revealed documents on the
one hand, and philosophical and scientific judgments and arguments,
the results of independent rational reflection, on the other. Revela-
tion and reason, religion and philosophy, faith and knowledge, author-
ity and independent reflection are the various expressions for the
dualism in mediaeval thought, which the philosophers and theologians
of the time endeavored to reduce to a monism or a unity.
Let us examine more intimately the character and content of the
two elements in the intellectual horizon of mediaeval Jewry. On the
side of revelation, rehgion, authority, we have the Bible, the Mishna,
the Tahnud. The Bible was the written law, and represented Uterally
the word of God as revealed to lawgiver and prophet; the Talmud
(including the Mishna) was the oral law, embodying the unwritten
commentary on the words of the Law, equally authentic with the
latter, contemporaneous with it in revelation, though not committed
to writing until many ages subsequently and until then handed down
by word of mouth; hence depending upon tradition and faith in tradi-
tion for its validity and acceptance. Authority therefore for the
Rabbanites was two-fold, the authority of the direct word of God
which was written down as soon as communicated, and about which
there could therefore be no manner of doubt; and the authority of
the indirect word of God as transmitted orally for many generations
before it was written down, requiring belief in tradition. By the
Karaites tradition was rejected, and there remained only belief in the
words of the Bible.
On the side of reason was urged first the claim of the testimony of
xiv INTRODUCTION
the senses, and second the vaHdity of logical inference as determined
by demonstration and syllogistic proof. This does not mean that the
Jewish thinkers of the middle ages developed unaided from without a
system of thought and a Weltanschauung, based solely upon their own
observation and ratiocination, and then found that the view of the
world thus acquired stood in opposition to the rehgion of the Bible
and the Talmud, the two thus requiring adjustment and reconciliation.
No! The so-called demands of the reason were not of their own mak-
ing, and on the other hand the relation between philosophy and reli-
gion was not altogether one of opposition. To discuss the latter pointfirst, the teachings of the Bible and the Talmud were not altogether
clear on a great many questions. Passages could be cited from the
religious documents of Judaism in reference to a given problem both
pro and con. Thus in the matter of freedom of the will one could
argue on the one hand that man must be free to determine his conductsince if he were not there would have been no use in giving him com-
mandments and prohibitions. And one could quote besides in favor of
freedom the direct statement in Deuteronomy 30, 19, "I call heaven
and earth to witness against you this day, that I have set before
thee life and death, the blessing and the curse: therefore choose life,
that thou mayest Hve, thou and thy seed." But on the other hand it
was just as possible to find Biblical statements indicating clearly that
God preordains how a person shall behave in a given case. Thus
Pharaoh's heart was hardened that he should not let the children of
Israel go out of Egypt, as we read in Exodus 7, 3: "And I will harden
Pharaoh's heart, and multiply my signs and my wonders in the land ofEgypt. But Pharaoh will not hearken unto you, and I will lay myhand upon Egypt, and bring forth my hosts, my people, the childrenof Israel, out of the land of Egypt by great judgments." Similarly
in the case of Sihon king of Heshbon we read in Deuteromony 2, 30:
"But Sihon king of Heshbon would not let us pass by him: for the
Lord thy God hardened his spirit, and made his heart obstinate, that
he might deliver him into thy hand, as at this day." And this is true
not merely of heathen kings, Ahab king of Israel was similarly en-
ticed by a divine instigation according to I Kings 22, 20: "And the
Lord said. Who shall entice Ahab, that he may go up and fall atRamoth-Gilead?"
INTRODUCTION xv
The fact of the matter is the Bible is not a systematic book, and
principles and problems are not clearly and strictly formulated even
in the domain of ethics which is its strong point. It was not therefore
a question here of opposition between the Bible and philosophy, or
authority and reason. What was required was rather a rational
analysis of the problem on its own merits and then an endeavor to
show that the conflicting passages in the Scriptures are capable of
interpretation so as to harmonize with each other and with the results
of rational speculation. To be sure, it was felt that the doctrine of
freedom is fundamental to the spirit of Judaism, and the philosophic
analyses led to the same result though in differing form, sometimes
dangerously approaching a thorough determinism, as in Hasdai
Crescas. ^
If such doubt was possible in an ethical problem where one would
suppose the Bible would be outspoken, the uncertainty was still
greater in purely metaphysical questions which as such were really
foreign to its purpose as a book of religion and ethics. While it was
clear that the Bible teaches the existence of God as the creator of the
universe, and of man as endowed with a soul, it is manifestly difficultto extract from it a rigid and detailed theory as to the nature of God,
the manner in which the world was created, the nature of the soul
and its relation to man and to God. As long as the Jews were self-centered and did not come in close contact with an alien civilization of
a philosophic mould, the need for a carefully thought out and con-
sistent theory on all the questions suggested was not felt. And thuswe have in the Talmudic literature quite a good deal of speculation
concerning God and man. But it can scarcely lay claim to being
rationalistic or philosophic, much less to being consistent. Nay, we
have in the Bible itself at least two books which attempt an anti-
dogmatic treatment of ethical problems. In Job is raised the question
whether a man's fortunes on earth bear any relation to his conduct
moral and spiritual. Ecclesiastes cannot make up his mind whether
life is worth Hving, and how to make the best of it once one finds him-
self aHve, whether by seeking wisdom or by pursuing pleasure. But
here too Job is a long poem, and the argument does not progress very
rapidly or very far. Ecclesiastes is rambling rather than analytic, and
on the whole mostly negative. The Talmudists were visibly puzzled
xvi INTRODUCTION
in their attitude to both books, wondered whether Job really existed
or was only a fancy, and seriously thought of excluding Ecclesiastes
from the canon. But these attempts at questioning the meaning of
life had no further results. They did not lead, as in the case of the
Greek Sophists, to a Socrates, a Plato or an Aristotle. Philo in Alexan-
dria and Maimonides in Fostat were the products not of the Bible and
the Talmud alone, but of a combination of Hebraism and Hellenism,
pure in the case of Philo, mixed with the spirit of Islam in Maimonides.
And this leads us to consider the second point mentioned above,
the nature and content of what was attributed in the middle ages
to the credit of reason. It was in reality once more a set of documents.
The Bible and Talmud were the documents of revelation, Aristotle
was the document of reason. Each was supreme in its sphere, and all
efforts must be bent to make them agree, for as revelation cannot be
doubted, so neither can the assured results of reason. But not all
which pretends to be the conclusion of reason is necessarily so in truth,
as on the other hand the documents of faith are subject to interpreta-
tion and may mean something other than appears on the surface.
That the Bible has an esoteric meaning besides the Kteral has its
source in the Talmud itself. Reference is found there to a mystic
doctrine of creation known as "Maase Bereshit" and a doctrine of
the divine chariot called "Maase Merkaba." ^ The exact nature of
these teachings is not known since the Talmud itself prohibits the
imparting of this mystic lore to any but the initiated, i. e., to those
showing themselves worthy; and never to more than one or two at a
time.^ But it is clear from the names of these doctrines that they
centered about the creation story in Genesis and the account of the
divine chariot in Ezekiel, chapters one and ten. Besides the Halaka
and Agada are full of interpretations of Biblical texts which are very
far from the literal and have httle to do with the context. Moreover,
the beliefs current among the Jews in Alexandria in the first century
B. C. found their way into mediaeval Jewry, that the philosophic
literature of the Greeks was originally borrowed or stolen from the
Hebrews, who lost it in times of storm and stress.^ This being the
case, it was believed that the Bible itself cannot be without some al-
lusions to philosophic doctrines. That the Bible does not clearly
teach philosophy is due to the fact that it was intended for the salva-
INTRODUCTION xvii
tion of all men, the simple as well as the wise, women and children
as well as male adults. For these it is sufficient that they know cer-
tain religious truths within their grasp and conduct themselves ac-
cording to the laws of goodness and righteousness. A strictly philo-sophic book would have been beyond their ken and they would have
been left without a guide in life. But the more intellectual and the
more ambitious are not merely permitted, nay they are obHgated to
search the Scriptures for the deeper truths found therein, truths akin
to the philosophic doctrines found in Greek literature; and the latter
will help them in understanding the Bible aright. It thus became a
duty to study philosophy and the sciences preparatory thereto,
logic, mathematics and physics; and thus equipped to approach the
Scriptures and interpret them in a philosophical manner. The study
of mediaeval Jewish rationahsm has therefore two sides to it, the analy-
sis of metaphysical, ethical and psychological problems, and the ap-
plication of these studies to an interpretation of Scripture.
Now let us take a closer glance at the rationalistic or philosophicliterature to which the Jews in the middle ages fell heirs. In 529 A. D.
the Greek schools of philosophy in Athens were closed by order of
Emperor Justinian. This did not, however, lead to the extinction of
Greek thought as an influence in the world. For though the West was
gradually dechning intellectually on account of the fall of Rome andthe barbarian invasions which followed in its train, there were signs
of progress in the East which, feeble at first, was destined in the course
of several centuries to illumine the whole of Europe with its enlight-
ening rays.
Long before 529, the date of the closing of the Greek schools, Greek
influence was introduced in the East in Asia and Africa.^ The whole
movement goes back to the days of Alexander the Great and the
victories he gained in the Orient. From that time on Greeks settled in
Asia and Africa and brought along with them Greek manners, the
Greek language, and the Greek arts and sciences. Alexandria, the
capital of the Ptolemies in Egypt after the death of Alexander, and
Antioch, the capital of Syria under the empire of the Seleucidae,
were well-known centres of Greek learning.
When Syria changed masters in 64 B. C. and became a Romanprovince, its form of civilization did not change, and the introduction
xviii INTRODUCTION
of Christianity had the effect of spreading the influence of the Greeks
and their language into Mesopotamia beyond the Euphrates. The
Christians in Syria had to study Greek in order to understand the
Scriptures of the Old and the New Testaments, the decrees and canonsof the ecclesiastical councils, and the writings of the Church Fathers.
Besides rehgion and the Church, the hberal arts and sciences, for
which the Greeks were so famous, attracted the interests of the Syrian
Christians, and schools were established in the ecclesiastical centres
where philosophy, mathematics and medicine were studied. These
branches of knowledge were represented in Greek literature, and hence
the works treating of these subjects had to be translated into Syriac
for the benefit of those who did not know Greek. Aristotle was the
authority in philosophy, Hippocrates and Galen in medicine.
The oldest of these schools was in Edessa in Mesopotamia, founded
in the year 363 by St. Ephrem of Nisibis. It was closed in 489 and the
teachers migrated to Persia where two other schools became famous,
one at Nisibis and the other at Gandisapora, A third school of phil-osophy among the Jacobite or Monophysite Christians was that con-
nected with the convent of Kinnesrin on the left bank of the Eu-
phrates, which became famous as a seat of Greek learning in the
beginning of the seventh century.
Christianity was succeeded in the Orient by Mohammedanism,
and this change led to even greater cultivation of Greek studies
on the part of the Syrians. The Mohammedan Caliphs employed
the Syrians as physicians. This was especially true of the Abbasid
dynasty, who came into power in 750. When they succeeded to the
CaUphate they raised Nestorian Syrians to ofl&ces of importance, and
the latter under the patronage of their masters continued their studies
of Greek science and philosophy and translated those writings into
Syriac and Arabic. Among the authors translated were, Hippocratesand Galen in medicine, Euclid, Archimedes and Ptolemy in mathe-
matics and astronomy, and Aristotle, Theophrastus and Alexander
of Aphrodisias in philosophy. In many cases the Greek writings were
not turned directly into Arabic but as the translators were Syrians,
the versions were made first into Syriac, and then from the Syriac
into Arabic. The Syrian Christians were thus the mediators between
the Greeks and the Arabs. The latter, however, in the course of time
INTRODUCTION xiy
far surpassed their Syrian teachers, developed important schools of
philosophy, became the teachers of the Jews, and with the help of the
latter introduced Greek philosophy as well as their own development
thereof into Christian Europe in the beginning of the thirteenth
century.
We see now that the impulse to philosophizing came from theGreeks,and not merely the impulse but the material, the matteras well as the method and the terminology. In the Aristotelian writ-
ings we find developed an entire system of thought. There is not a
branch of knowledge dealing with fundamental principles which is not
there represented. First of all Aristotle stands alone as the discoverer
of the organon of thought, the tool which we all employ in our reason-
ing and reflection; he is the first formulator of the science and art of
logic. He treats besides of the principles of nature and natural phe-nomena in the Physics and the treatise on the Heavens. He discussesthe nature of the soul, the senses and the intellect in his ' Psychology."
In the ' History of Animals" and other minor works we have a treat-
ment of biology. In the Nikomachean and Eudemian Ethics he analy-
zes the meaning of virtue, gives a list and classification of the virtues
and discusses the summum bonum or the aim of human life. Finally inthe Metaphysics we have an analysis of the fundamental notions of
being, of the nature of reality and of God.
The Jews did not get all this in its purity for various reasons. In
the first place it was only gradually that the Jews became acquainted
with the wealth of Aristotelian material. We are sure that AbrahamIbn Daud, the forerunner of Maimonides, had a thorough familiarity
with the ideas of Aristotle; and those who came after him, for example
Maimonides, Gersonides, Hasdai Crescas, show clearly that they were
deep students of the ideas represented in the writings of the Stagirite.
But there is not the same evidence in the earlier writings of Isaac
Israeli, Saadia, Joseph Ibn Zaddik, Gabirol, Bahya Ibn Pakuda,
Judah Halevi. They had picked up Aristotelian ideas and principles,
but they had also absorbed ideas and concepts from other schools,
Greek as well as Arabian, and unconsciously combined the two.
Another explanation for the rarity of the complete and unadulter-
ated Aristotle among the Jewish thinkers of the middle ages is that
people in those days were very uncritical in the matter of historical
XX INTRODUCTION
facts and relations. Historical and literary criticism was altogether
unknown, and a number of works were ascribed to Aristotle which
did not belong to him, and which were foreign in spirit to his mode of
thinking. They emanated from a different school of thought with
different presuppositions. I am referring to the treatise called the"Theology of Aristotle,"^ and that known as the "Liber de Causis."^
Both were attributed to Aristotle in the middle ages by Jews and
Arabs alike, but it has been shown recently ^ that the former represents
extracts from the works of Plotinus, the head of the Neo-Platonic
school of philosophy, while the latter is derived from a treatise of
Proclus, a Neo-Platonist of later date.
Finally a third reason for the phenomenon in question is that the
Jews were the pupils of the Arabs and followed their lead in adapting
Greek thought to their own intellectual and spiritual needs. It so
happens therefore that even in the case of Abraham Ibn Daud, Mai-
monides and Gersonides, who were without doubt well versed in
Aristotelian thought and entertained not merely admiration but
reverence for the philosopher of Stagira, we notice that instead of
reading the works of Aristotle himself, they preferred, or were obliged
as the case may be, to go to the writings of Alfarabi, Avicenna and
Averroes for their information on the views of the philosopher. In
the case of Gersonides this is easily explained. It seems he could read
neither Latin nor Arabic^ and there was no Hebrew translation of the
text of Aristotle. Averroes had taken in the fourteenth century the
place of the Greek philosopher and instead of reading Aristotle all
students read the works of the Commentator, as Averroes was called.
Of course the very absence of a Hebrew translation of Aristotle's
text proves that even among those who read Arabic the demand for
the text of Aristotle was not great, and preference was shown for the
works of the interpreters, compendists and commentators, like Alfarabi
and Avicenna. And this helps us to understand why it is that Ibn
Daud and Maimonides who not only read Arabic but wrote their
philosophical works in Arabic showed the same preference for the
secondhand Aristotle. One reason may have been the lack of historical
and literary criticism spoken of above, and the other the difficulty
of the Arabic translations of Aristotle. Aristotle is hard to translate
into any language by reason of his peculiar technical terminology;
INTRODUCTION xxi
and the difficulty was considerably enhanced by the fact that the
Syriac in many cases stood between the original Greek and the Arabic,
and in the second place by the great dissimilarity between the Semitic
language and its Indo-European original. This may have made thecopies of Aristotle's text rare, and gradually led to their disuse. The
great authority which names like Alfarabi, Avicenna and Averroes
acquired still further served to stamp them as the approved expositors
of the AristoteHan doctrine.
Among the Arabs the earliest division based upon a theoreticalquestion was that of the parties known as the ''Kadariya" and the
"Jabariya." ^ The problem which was the cause of the difference
was that of free will and determinism. Orthodox Islam favored the
idea that man is completely dependent upon the divine will, and thatnot only his destiny but also his conduct is determined, and his own
will does not count. This was the popular feehng, though as far as the
Koran is concerned the question cannot be decided one way or the
other, as it is not consistent in its stand, and arguments can be drawn
in plenty in favor of either opinion. The idea of determinism, however,
seemed repugnant to many minds, who could not reconcile this withtheir idea of reward and punishment and the justice of God. How is itpossible that a righteous God would force a man to act in a certainmanner and then punish him for it? Hence the sect of the " Kadariya,"
who were in favor of freedom of the will. The Jabariya were the
determinists.
This division goes back to a very early period before the introduc-
tion of the Aristotelian philosophy among the Arabs, and hence owes
its inception not to reason as opposed to religious dogma, but to a
pious endeavor to understand clearly the rehgious view upon so im-
portant a question.
From the Kadariya, and in opposition to the AristoteUan move-
ment which had in the meantime gained ground, developed the school
of theologians known as the "Mutakallimun." They were the first
among the Arabs who dehberately laid down the reason as a source
of knowledge in addition to the authority of the Koran and the
"Sunna" or tradition. They were not freethinkers, and their object
was not to oppose orthodoxy as such. On the contrary, their purposewas to purify the faith by freeing it from such elements as obscured
xxii INTRODUCTION
in their minds the purity of the monotheistic tenet and the justice of
God. They started where the Kadariya left off and went further.
As a school of opposition their efforts were directed to prove the
creation of the world, individual providence, the reality of miracles,
as against the "philosophers," i. e., the Aristotehans, who held to the
eternity of motion, denied God's knowledge of particulars, and in-
sisted on the unchanging character of natural law.
For this purpose they placed at the basis of their speculations not
the AristoteHan concepts of matter and form, the former uncreated
and continuous, but adopted the atomistic theory of Democritus,
denied the necessity of cause and effect and the validity of natural
law, and made God directly responsible for everything that happened
every moment in life. God, they said, creates continually, and he is
not hampered by any such thing as natural law, which is merely our
name for that which we are accustomed to see. Whenever it rains we
are accustomed to see the ground wet, and we conclude that there is
a necessary connection of cause and effect between the rain and the
wetness of the ground. Nothing of the kind, say the Mutakallimun,
or the Mu tazila, the oldest sect of the school. It rains because Godwilled that it should rain, and the ground is wet because God wills it
shall be wet. If God willed that the ground should be dry following
a rain, it would be dry; and the one is no more and no less natural
than the other. Miracles cease to be miracles on this conception of
natural processes. Similarly the dogma of creation is easily vindi-
cated on this theory as against the Aristotelian doctrine of eternity
of the world, which follows from his doctrine of matter and form, as
we shall have occasion to see later.
The Mu tazila were, however, chiefly known not for their principlesof physics but for their doctrines of the unity of God and his justice.
It was this which gave them their name of the "Men of Unity andJustice," i. e., the men who vindicate against the unenlightened views
of popular orthodoxy the unity of God and his justice.
The discussion of the unity centered about the proper interpreta-
tion of the anthropomorphic passages in the Koran and the doctrine
of the divine attributes. When the Koran speaks of God's eyes,ears, hands, feet; of his seeing, hearing, sitting, standing, walking,
being angry, smiling, and so on, must those phrases be understood
INTRODUCTION xxiii
literally? If so God is similar to man, corporeal like him, and swayed
by passions. This seemed to the Mu tazila an unworthy conceptionof God. To vindicate his spirituality the anthropomorphic passages
in the Koran must be understood metaphorically.
The other more difficult question was in what sense can attributes
be ascribed to God at all? It is not here a question of anthropomor-
phism. If I say that God is omniscient, omnipotent and a living God,
I attribute to God life, power, knowledge. Are these attributes the
same with God's essence or are they different? If different (and they
must be eternal since God was never without them), then we have
more than one eternal being, and God is dependent upon others. If
they are not different from God's essence, then his essence is not a
strict unity, since it is composed of life, power, knowledge; for life is
not power, and power is not knowledge. The only way to defend the
unity of God in its absolute purity is to say that God has no attri-
butes, i. e., God is omniscient but not through knowledge as his
attribute; God is omnipotent but not through power as his attribute,
and so on. God is absolutely one, and there is no distinction between
knowledge, power, and life in him. They are all one, and are his
essence.
This seemed in opposition to the words of the Koran, which fre-
quently speaks of God's knowledge, power, and so on, and was ac-
cordingly condemned as heretical by the orthodox.
In the tenth century a new sect arose named the "Ashariya" after
Al-Ashari, its founder. This was a party of moderation, and tended to
conciliate orthodoxy by not going too far in the direction of rationalis-
tic thinking. They solved the problem by saying, "God knows
through a knowledge which is not different from his essence."
The other problem to which the Mu'tazila devoted their attention
was that of the justice of God. This was in line with the efforts of the
Kadariya before them. It concerned itself with the doctrine of free
will. They defended man's absolute freedom of action, and insisted
on justice as the only motive of God's deahngs with men. God must
be just and cannot act otherwise than in accordance with justice.
In reference to the question of the nature of good and evil, the
orthodox position was that good is that which God commands, evil
that which God forbids. In other words, nothing is in itself good or
xxiv INTRODUCTION
evil, the ethical character of an act is purely relative to God's attitude
to it. If God were to command cannibalism, it would be a good act.
The Mu'tazila were opposed to this. They believed in the absolute
character of good and evil. What makes an act good or bad is reason,
and it is because an act is good that God commands it, and not the
reverse.
The foregoing account gives us an idea of the nature of the Mu'tazi-
lite discussions of the two problems of God's unity and God's justice.
Their works were all arranged in the same way. They were divided
into two parts, one dealing with the question of the unity, and the
other with that of justice. The proofs of the unity were preceded by
the proofs of God's existence, and the latter were based upon a demon-
stration that the world is not eternal, but bears traces of having come
to be in time. These are the earmarks by which a Mu'taziHte book
could be recognized, and the respect for them on the part of the
philosophers, i. e., the AristoteUans, was not great. The latter did not
consider them worthy combatants in a philosophical fight, claiming
that they came with preconceived notions and arranged their concep-
tions of nature to suit the religious beUefs which they desired to de-
fend. Maimonides expresses a similar judgment concerning their
worthlessness as philosophical thinkers.^^
This school of the Mutakallimun, or of the more important part of
it known as the Mu'tazila, is of great interest for the history of Jewish
rationaHsm. In the first place their influence on the early Jewish
philosophers was great and unmistakable. It is no discovery of a
late day but is well known to Maimonides who is himself, as has just
been said and as will appear with greater detail later, a strong opponent
of these to him unphilosophical thinkers. In the seventy-first chapter
of his "Guide of the Perplexed," he says, "You will find that in the
few works composed by the Geonim and the Karaites on the unity of
God and on such matter as is connected with this doctrine, they fol-
lowed the lead of the Mohammedan Mutakallimun. ... It also
happened, that at the time when the Mohammedans adopted this
method of the Kalam, there arose among them a certain sect, called
Mu'tazila. In certain things our scholars followed the theory and the
method of these Mu'tazila."
Thanks to the researches of modern Jewish and non-Jewish scholars
INTRODUCTION XXV
we know now that the Rabbanite thinker Saadia and the Karaite
writers, like Joseph Al Basir and Jeshuah ben Judah, are indebted
far more to the Mohammedan Mu'tazihtes than would appear fromMaimonides's statement just quoted. The Rabbanites being staunch
adherents of the Talmud, to the influence of which they owed a
national and religious self-consciousness much stronger than that of
the Karaites, who rejected the authority of tradition, did not allow
themselves to be carried away so far by the ideas of the Mohammedanrationalists as to become their slavish followers. The Karaites are less
scrupulous; and as they were the first among the Jews to imitate the
Mu'tazila in the endeavor to rationalize Jewish doctrine, they adopted
their views in all details, and it is sometimes impossible to tell from the
contents of a Karaite Mu'tazilite work whether it was written by a
Jew or a Mohammedan. The arrangement of the work in the two
divisions of "Unity" and "Justice," the discussion of substance and
accident, of the creation of the world, of the existence, unity and
incorporeality of God, of his attributes, of his justice, and of human
free will, are so similar in the two that it is external evidence alone
to which we owe the knowledge of certain Karaite works as Jewish.
There are no mediaeval Jewish works treating of religious and theolog-
ical problems in which there is so much aloofness, such absence of
theological prepossession and religious feeling as in some Karaite
writings of Mu'tazilite stamp. Cold and unredeemed logic gives the
tone to the entire composition.
Another reason for the importance of the Mu tazilite school for thehistory of Jewish thought is of recent discovery. Schreiner has sug-
gested ^^ that the origin of the Mu' tazilite movement was due to the
influence of learned Jews with whom the Mohammedans came in con-tact, particularly in the city of Basra, an important centre of the
school. The reader will recall that the two main doctrines of the
Mu tazila were the unity of God and his justice. The latter reallysignified the freedom of the will. That these are good Jewish views
would of course prove nothing for the origin of similar opinions among
the Mohammedans. For it is not here a question simply of the dog-
matic belief in Monotheism as opposed to polytheism. Mohammed-anism is as a religion Monotheistic and we know that Mohammed wasindebted very much to Jews and Judaism. We are here concerned
xxvi INTRODUCTION
with the origin of a rationalistic movement which endeavors to defend
a spiritual conception of God against a crude anthropomorphism, to
vindicate a conception of his absolute unity against the threatened
multiplication of his essence by the assumption of eternal attributes,
and which puts stress upon God's justice rather than upon his omnip-
otence so as to save human freedom. Another doctrine of the
Mu tazila was that the Koran was not eternal as the orthodox be-lieved, but that it was created. Now we can find parallels for mostof these doctrines. Anthropomorphism was avoided in the Aramaic
translations of the Pentateuch, also in certain changes in the Hebrew
text which are recorded in Rabbinical literature, and known as
"Tikkune Soferim," or corrections of the Scribes. ^^ Concern for
maintaining the unity of God in its absolute purity is seen in the care
with which the men of the Agada forbid any prayer which may havea semblance, however remote, of dualism. ^^ The freedom of the will is
clearly stated in the Rabbinic expression, "All is in the hands of Godexcept the fear of Heaven." ^^ And an apparently deterministic pas-sage in Job 23, 13, "But he is one and who can turn him, and what
his soul desireth, even that he doeth, " is explained by Rabbi Akiba
in the following manner, "It is not possible to answer the words of
him who with his word created the world, for he rules all things withtruth and with righteousness." ^^ And we find a parallel also for thecreation of the Koran in the Midrashic statement that the Torah is one
of the six or seven things created before the world.^'^
These parallels alone would not be of much weight, but they are
strengthened by other considerations. The Mu'tazilite movement
seems to have developed among the ascetic sects, with the leaders of
whom its founders were in close relation. ^^ The ascetic literaturebears unmistakable traces of having been influenced by the Halaka
and the Agada. ^^ Moreover, there is a Mohammedan tradition ortwo to the effect that the doctrine of the creation of the Koran and
also of the rejection of anthropomorphism goes back to a Jew, Lebid-
ibn Al-A'sam.2
More recently still * C. H. Becker proved from a study of certain
Patristic writings that the polemical literature of the Christians
played an important role in the formation of Mohammedan dogma,
*CJ. Zeitschrift fiir Assyriologie, 1912, 175 ff.
INTRODUCTION sxvii
and he shows conclusively that the form in which the problem of
freedom was discussed among the Mohammedans was taken from
Christianity, The question of the creation or eternity of the Koran
or word of Allah, is similarly related to the Christian idea of the
eternal Logos, who is on the one hand the Word and the Wisdom,
and is on the other identified with Jesus Christ. And the same thing
holds of the doctrine of attributes. It played a greater role in Chris-
tian dogma than it ever did in Judaism prior to the philosophic era
in the middle ages. To be sure, the Patristic writers were much in-
debted to Philo, in whose writings the germ of the mediaeval doctrine
of attributes is plainly evident. But the Mohammedan schools did
not read Philo. It would seem, therefore, that Schreiner's view must
be considerably modified, if not entirely rejected, in view of the later
evidence adduced by Becker.
The more extreme doctrines, however, of the more orthodox Ash-
ariya, such as the denial of natural law and the necessity of cause and
effect, likewise the denial of man's abihty to determine his actions,
none of the Jews accepted. Here we have again the testimony of
Maimonides, who, however, is not inclined to credit this circumstance
to the intelligence and judgment of his predecessors, but to chance.
His words are, "Although another sect, the Ashariya, with their own
pecuhar views, was subsequently established among the Moham-
medans, you will not find any of these views in the writings of our
authors; not because these authors preferred the opinions of the first
named sect to those of the latter, but because they chanced first to
become acquainted with the theory of the Mu'tazila, which they
adopted and treated as demonstrated truth."^^
The influence of the Kalam is present in greater or less degree in the
philosophers up to Abraham Ibn Daud and Maimonides. The latter
gave this system its death blow in his thoroughgoing criticism, ^^ and
thenceforth Aristotelianism was in possession of the field until that
too was attacked by Hasdai Crescas.
Another sect of the Mohammedans which had considerable in-
fluence on some of the Jewish philosophical and ethical writers are the
ascetics and the Sufis who are related to them. The latter developed
their mode of life and their doctrines under the influence of the Chris-
tian monks, and are likewise indebted to Indian and Persian ideas.^^
xxviii INTRODUCTION
In their mode of life they belong to the class of ascetics and preach
abstinence, indifference to human praise and blame, love of God and
absolute trust in him even to the extent of refraining from all effort in
one's own behalf, and in extreme cases going so far as to court danger.
In theoretical teaching they adopted the emanatistic doctrine of the
Neo-Platonic School. This has been called dynamic Pantheism. It is
Pantheism because in its last analysis it identifies God with the
universe. At the same time it does not bring God directly in contact
with the world, but only indirectly through the powers or Bvvdfiei^^
hence dynamic Pantheism. These powers emanate successively from
the highest one, forming a chain of intermediate powers mediating
between God and the world of matter, the links of the chain growing
dimmer and less pure as they are further removed from their origin,
while the latter loses nothing in the process. This latter condition
saves the Neo-Platonic conception from being a pure system of emana-
tion like some Indian doctrines. In the latter the first cause actually
gives away something of itself and loses thereby from its fulness. The
process in both systems is explained by use of analogies, those of the
radiation of light from a luminous body, and of the overflowing of a
fountain being the most common.
The chief exponent of the ethics of the Sufis in mediaeval Jewish
literature is Bahya Ibn Pakuda. In his ethical work "The Duties of
the Hearts," he lays the same stress on intention and inwardness in
rehgious life and practice as against outward performance with the
limbs on the one hand and dry scholasticism on the other, as do the
Sufis. In matters of detail too he is very much indebted to this Arab
sect from whose writings he quotes abundantly with as well as without
acknowledgment of his sources except in a general way as the wise
men. To be sure, he does not follow them slavishly and rejects the
extremes of asceticism and unworldly cynicism which a great many
of the Sufis preached and practiced. He is also not in sympathy with
their mysticism. He adopts their teachings only where he can support
them with analogous views as expressed in the Rabbinical writings,
which indeed played an important role in Mohammedan ascetic lit-
erature, being the source of many of the sayings found in the latter. ^^
The systems of thought which had the greatest influence upon
Jewish as well as Mohammedan theology, were the great systems of
INTRODUCTION xxix
Plato (especially as developed in Neo-Platonism) and Aristotle.
These two philosophies not merely affected the thinking of Jew and
Mohammedan but really transformed it from rehgious and ethical
discussions into metaphysical systems. In the Bible and similarly in
the Koran we have a purely personal view of God and the world. God
is a person, he creates the worldout of nothing to be surebut never-theless he is thought of doing it in the manner in which a person does
such things with a will and a purpose in time and place. He puts a
soul into man and communicates to him laws and prohibitions. Man
must obey these laws because they are the will of God and are good,
and he will be rewarded and punished according to his attitude in
obedience and disobedience. The character of the entire point of view
is personal, human, teleological, ethical. There is no attempt made
at an impersonal and objective analysis of the common aspects of all
existing things, the elements underlying all nature. Nor is there any
conscious effort at a critical classification of the various kinds of things
existing in nature beyond the ordinary and evident classification found
in Genesisheaven and earth; in heaven, sun, moon and stars; onearth, grass, fruit trees, insects, water animals, birds, quadrupeds,
man. Then light and darkness, the seasons of the year, dry land and
water.
In Greek philosophy for the first time we find speculations concern-
ing the common element or elements out of which the world is made
the material cause as Aristotle later called it. The Sophists and Soc-
rates gave the first impulse to a logical analysis of what is involved in
description or definition. The concept as denoting the essence of a
thing is the important contribution Socrates made to knowledge.
Plato objectified the concept, or rather he posited an object as the
basis of the concept, and raised it out of this world of shadows to an
inteUigible world of realities on which the world of particulars depends.
But it was Aristotle who made a thoroughgoing analysis of thing as
well as thought, and he was the master of knowledge through the
middle ages alike for Jew, Christian and Mohammedan.
First of all he classified all objects of our experience and found that
they can be grouped in ten classes or categories as he called them.
Think of any thing you please and you will find that it is either an
object in the strict sense, i. e., some thing that exists independently
XXX INTRODUCTION
of anything else, and is the recipient of quahties, as for example a man,
a mountain, a chair. Or it is a quantity, like four, or cubit; or a qual-
ity, like good, black, straight; or a relation like long, double, master,
slave; and so on throughout the ten categories. This classification
applies to words and thoughts as well as to things. As an analysis of
the first two it led him to more important investigations of speech and
thinking and arguing, and resulted in his system of logic, which is
the most momentous discovery of a single mind recorded in history.
As applied to things it was followed by a more fundamental analysis of
all real objects in our world into the two elements of matter and form.
He argued as follows: nothing in the material world is permanent as
an individual thing. It changes its state from moment to moment
and finally ceases to be the thing it was. An acorn passes a number of
stages before it is ripe, and when it is placed in the ground it again
changes its form continually and then comes out as an oak. In ar-
tificial products man in a measure imitates nature. He takes a block
of marble and makes a statue out of it. He forms a log into a bed.
So an ignorant man becomes civilized and learned. All these examples
illustrate change. What then is change? Is there any similarity in
all the cases cited? Can we express the process of change in a formula
which will apply to all instances of change? If so, we shall have gained
an insight into a process of nature which is all-embracing and universal
in our experience. Yes, we can, says Aristotle. Change is a play of
two elements in the changing thing. When a thing affected with one
quality changes into a thing with the opposite quahty, there must
be the thing itself without either of the opposite qualities, which is
changing. Thus when a white fence becomes black, the fence itself
or that which undergoes the change is something neither white nor
black. It is the uncolored matter which first had the form of white
and now lost that and took on the form of black. This is typical of all
change. There is in all change ultimately an unchanging substratum
always the same, which takes on one quality after another, or as
Aristotle would say, one form after another. This substratum is
matter, which in its purity is not affected with any quality or form, of
which it is the seat and residence. The forms on the other hand come
and go. Form does not change any more than matter. The changing
thing is the composite of matter and form, and change means separa-
INTRODUCTION xxxi
tion of the actual components of which one, the form, disappears
and makes room for its opposite. In a given case, say, when a statue
is made out of a block of marble, the matter is the marble which lost
its original form and assumed the form of a statue. In this case the
marble, if you take away both the previous form and the present, will
still have some form if it is still marble, for marble must have certain
qualities if it is to be marble. In that case then the matter underlying
the change in question is not pure matter, it is already endowed with
some primitive form and is composite. But marble is ultimately
reducible to the four elements, fire, air, water, earth, which are simpler;
and theoretically, though not in practice, we can think away all form,
and we have left only that which takes forms but is itself not any form.
This is matter.
Here the reader will ask, what kind of thing is it that has no form
whatsoever, is it not nothing at all? How can anything exist withoutbeing a particular kind of thing, and the moment it is that it is no
longer pure matter. Aristotle's answer is that it is true that pure
matter is never found as an objective existence. Point to any real
object and it is composed of matter and form. And yet it is not true
that matter is a pure figment of the imagination; it has an existence of
its own, a potential existence. And this leads us to another important
conception in the Aristotelian philosophy.
PotentiaHty and actuality are correlative terms corresponding to
matter and form. Matter is the potential, form is the actual. What-
ever potentiaHties an object has it owes to its matter. Its actual
essence is due to its form. A thing free from matter would be all thatit is at once. It would not be liable to change of any kind, whether
progress or retrogression. All the objects of our experience in the
sublunar world are not of this kind. They realize themselves gradu-
ally, and are never at any given moment all that they are capable of
becoming. This is due to their matter. On the other hand, purematter is actually nothing. It is just capacity for being anything, and
the moment it is anything it is affected with form.
It is clear from this account that matter and form are the bases of
sublunar life and existence. No change, no motion without matterand form. For motion is presupposed in all kinds of change. If
then all processes of life and death and change of all kinds presuppose
xxxii INTRODUCTION
matter and form, the latter cannot themselves be liable to genesis and
decay and change, for that would mean that matter is composed of
matter and form, which is absurd. We thus see how Aristotle is ledto believe in the eternity of matter and motion, in other words, the
eternity of the world processes as we know them.
Motion is the realization of the potential qua potential. This is
an Aristotelian definition and applies not merely to motion in the
strict sense, i. e., movement in place, or motion of translation,
but embraces all kinds of change. Take as an example the warming
of the air in a cold room. The process of heating the room is a kind
of motion; the air passes from a state of being cold to a state of being
warm. In its original state as cold it is potentially warm, i. e., it is
actually not warm, but has the capacity of becoming warm. At the
end of the process it is actually warm. Hence the process itself is
the actualization of the potential. That which is potential cannot
make itself actual, for to make itself actual it must be actual, which
is contrary to the hypothesis of its being potential. Potentiality and
actuality are contradictory states and cannot exist side by side in the
same thing at the same time in the same relation. There must there-
fore be an external agent, itself actual, to actualize a potential. Thus,
in the above illustration, a cold room cannot make itself warm. There
must be some agency itself actually warm to cause the air in the room
to pass from cold to warm. This is true also of motion in place, that
a thing cannot move itself and must be moved by something else.
But that something else if itself in motion must again be moved by
something else. This process would lead us to infinity. In order
that a given thing shall be in motion, it would be necessary for an
infinite number of things to be in motion. This is impossible, because
there cannot be an infinite number of things all here and now. It
is a contradiction in terms. Hence if anything is to move at all,
there must be at the end of the finite chain a link which while causing
the next link to move, is itself unmoved. Hence the motion existing
in the world must be due ultimately to the existence of an unmoved
mover. If this being causes motion without being itself in motion
it does not act upon the bodies it moves as one body acts upon another,
for a body can move another body only by being itself in motion. The
manner in which the unmoved mover moves the world is rather to be
INTRODUCTION xxxiii
conceived on the analogy of a loved object moving the loving object
without itself being moved. The person in love strives to approach
and unite with the object of his love without the latter necessarily
being moved in turn. This is the way in which Aristotle conceives
of the cause of the world's motion. There is no room here for the
creation of the world. Matter is eternal, motion is eternal, and there
is an eternal mind for the love of which all motions have been going
on eternally.
The unmoved mover, or God, is thus not body, for no body can
move another body without being itself in motion at the same time.Besides, all body is finite, i. e., it has a finite magnitude. A body ofinfinite magnitude is an impossibihty, as the very essence of body is
that it must be bounded by surfaces. A finite body cannot have aninfinite power, as Aristotle proves, though we need not at present
go into the details of his proof. But a being which causes eternal
motion in the world must have an infinite power to do this. Hence
another proof that God is not corporeal.
If God is not subject to motion, he is not subject to change of anykind, for change involves motion. As matter is at the basis of all
change God is without matter, hence he is pure form, i. e., pure ac-tuahty without the least potentiahty. This means that he is what he
is wholly all the time; he has no capacities of being what he is at any
time not. But if he is not corporeal, the nature of his actuahty or
activity must be Thought, pure thinking. And the content of histhought cannot vary from topic to topic, for this would be change,
which is foreign to him. He must be eternally thinking the samethought; and the highest thought it must be. But the highest thought
is himself; hence God is pure thought thinking himself, thoughtthinking thought.
The universe is in the shape of a sphere with the earth stationaryin the centre and the heavens revolving around it exactly as appears
to us. The element earth is the heaviest, hence its place is below or,which is the same thing, in the centre. This is its natural place; and
its natural motion when away from the centre is in a straight line
toward the centre. Water is the next heaviest element and its natural
place is just above earth; hence the water in the world occupies a
position spherical in shape round about the earth, i. e., it forms a
xxxiv INTRODUCTION
hollow sphere concentric with the earth. Next comes the hollow
sphere of air concentric with the other two. Its natural motion when
away from its place in the direction of the earth is in a straight line
toward the circumference of the world, not however going beyond
the sphere of the lightest element of all, namely, fire. This has its
natural place outside of the other elements, also in the form of a hollow
sphere concentric with the other three. Its natural motion is in a
straight line away from the centre of the world and in the direction
of the circumference. Our earth, water, air and fire are not really
the elements in their purity. Each one has in it also mixtures of
the other three elements, the one which gives it the name predom-
inating.
All minerals, plants and animals are formed from these four elements
by various combinations, all together forming the sublunar world,
or the world of generation and decay. No individual thing in thisworld is permanent. All are subject to change and to ultimate de-
struction, though the destruction of one thing is the genesis of another.
There is no annihilation.
The causes of the various combinations of the elements and the
generation and destruction of mineral, plant and animal resulting
therefrom, are the motions of the heavenly bodies. These are made
of a purer substance than that of the four elements, the ether. This
is proven by the fact that the heavenly bodies are not subject to
change or destruction. They are all permanent and the only change
visible in them is change of place. But even their motions are different
from those of the four elements. The latter are in a straight line
toward the centre or away from it, whereas the heavenly bodies move
in a circle eternally around the centre. This is another proof that
they are not composed of the same material as sublunar bodies.
The heavens consist of transparent spheres, and the stars as well
as the planets are set in them and remain fixed. The motions of the
heavenly bodies are due to the revolutions of the spheres in which
they are set. These spheres are hollow and concentric. The outer-
most sphere forming the outer limit of the universe (the world is finite
according to Aristotle) is studded with the fixed stars and moves
from east to west, making a complete revolution in twenty-four
hours. This motion is transmitted to the other spheres which carry
INTRODUCTION xxxv
the planets. Since, however, we notice in the sun, moon and the other
planetary bodies motions in the contrary direction in addition to that
from east to west, there must be other spheres having the motions
apparent to us in the positions of the planets borne by them. Thus a
given body like the sun or moon is set in more than one sphere, each
of which has its own proper motion, and the star's apparent motion
is the resultant of the several motions of its spheres. Without entering
into further details concerning these motions, it will be sufficient for
us to know that Aristotle counted in all fifty-five spheres. First
came the sphere of the fixed stars, then in order the spheres of Saturn,
Jupiter, Mars, Mercury, Venus, Sun, Moon.
God himself sets the outer sphere in motion, or rather is the eternal
cause of its motion, as the object of its desire; and in the same way
each of the other motions has also its proper mover, likewise a pure
form or spirit, which moves its sphere in the same incorporeal and
unmoved manner as God.
Thus we have in the supra-lunar world pure forms without mat-
ter in God and the spirits of the spheres, whereas in the sublunar
world matter and form are inseparable. Neither is found separately
without the other.
In man's soul, however, or rather in his intellect we find a form
which combines in itself the peculiarities of sublunar as well as celestial
forms. When in contact with the human body it partakes of thenature of other sublunar forms exhibiting its activity through matter
and being inseparable from it. But it is not destroyed with the death
of the body. It continues as a separate form after death.
The soul, Aristotle defines as the first entelechy of the body. The
term entelechy which sounds outlandish to us may be replaced by
the word realization or actualization and is very close in meaning to
the Aristotelian use of the word form. The soul then, according
to Aristotle, is the realization or actualization or form of the body.
The body takes the place of matter in the human composite. It has
the composition and the structure which give it the capacity for per-
forming the functions of a human being, as in any other composite,
say an axe, the steel is the matter which has the potentiality or capac-
ity of being made into a cutting instrument. Its cutting function
is the form of the axewe might almost say the soul of the axe, if
xxxvi INTRODUCTION
it were not for the circumstance that it cannot do its own cutting; it
must be wielded by someone else.
So far then the human soul forms an inseparable unit with the body
which it informs. As we do not think of the cutting function of an
axe existing apart from the axe, so neither can we conceive of sensa-
tion, emotion or memory as existing without a body. In so far as the
soul is this it is a material form like the rest, and ceases with the dis-
solution of the body. But the soul is more than this. It is also a
thinking faculty. As such it is not in its essence dependent upon the
body or any corporeal organ. It comes from without, having existed
before the body, and it will continue to exist after the body is no more.
That it is different from the sensitive soul is proven by the fact that
the latter is inherent in the physical organ through which it acts,
being the form of the body, as we have seen. And hence when an
unusually violent stimulus, say a very bright light or a very loud sound,
impinges upon the sense organ, the faculty of sight or hearing is
injured to such an extent that it cannot thereafter perceive an ordinary
sight or sound. But in the rational faculty this is not the case. The
more intense the thought occupying the thinking soul, the more ca-
pable it becomes of thinking lesser thoughts. To be sure, the reason
seems to weaken in old age, but this is due to the weakening of the
body with which the soul is connected during life; the soul itself is
just as active as ever.
We must, however, distinguish between two aspects of the rationalsoul, to one of which alone the above statements apply. Thought
differs from sensation in that the latter perceives the particular form
of the individual thing, whereas the former apprehends the essential
nature of the object, that which constitutes it a member of a certain
class. The sense of sight perceives a given individual man; thought or
reason understands what it is to be a member of the human species.
Reason therefore deals with pure form. In man we observe the
reason gradually developing from a potential to an actual state. The
objects of the sense with the help of the faculties of sensation, memory
and imagination act upon the potential intellect of the child, which
without them would forever remain a mere capacity without ever
being realized. This aspect of the reason then in man, namely, the
passive aspect which receives ideas, grows and dies with the body.
INTRODUCTION xxxvii
But there is another aspect of the reason, the active reason which has
nothing to do with the body, though it is in some manner resident in
it during the life of the latter. This it is which enables the passive
intellect to become realized. For the external objects as such are in-
sufficient to endow the rational capacity of the individual with actual
ideas, any more than a surface can endow the sense of sight with
the sensation of color when there is no hght. It is the active intellect
which develops the human capacity for thinking and makes it active
thought. This alone, the active intellect, is the immortal part of
man.
This very imperfect sketch of Aristotle's mode of approach to the
ever-living problems of God, the universe and man shows us the widediversity of his method from that with which the Jews of Bibhcal and
Rabbinic tradition were identified. Greek philosophy must have
seemed a revelation to them, and we do not wonder that they became
such enthusiastic followers of the Stagirite, feeUng as they must have
done that his method as well as his results were calculated to enrich
their intellectual and spiritual life. Hence the current belief of an
original Jewish philosophy borrowed or stolen by the Greeks, and still
betraying its traces in the Bible and Talmud was more than welcome
to the enlightened spirits of the time. And they worked this unhis-torical belief to its breaking point in their Biblical exegesis.
Aristotle, however, was not their only master, though they did not
know it. Plotinus in Aristotelian disguise contributed not a little to
their conception of God and his relation to the universe. The so-called
"Theology of Aristotle" ^^ is a Plotinian work, and its Pantheistic
point of view is in reahty foreign to Aristotle's dualism. But the middle
ages were not aware of the origin of this treatise, and so they attrib-
uted it to the Stagirite philosopher and proceeded to harmonize it
with the rest of his system as they knew it.
Aristotle's system may be called theistic and duahstic; Plotinus's ispantheistic and monistic. In Aristotle matter is not created by or
derived from God, who is external to the universe. Plotinus derives
everything from God, who through his powers or activities pervades
all. The different gradations of being are static in Aristotle, dynamic
in Plotinus. Plotinus assumes an absolute cause, which he calls the
One and the Good. This is the highest and is at the top of the scale of
xxxviii INTRODUCTION
existence. It is superior to Being as well as to Thought, for the latter
imply a duality whereas unity is prior to and above all plurality.
Hence we can know nothing as to the nature of the Highest. Wecan know only that He is, not what he is. From this highest Beingproceeds by a physical necessity, as light from a luminous body or
water from an overflowing spring, a second hypostasis or substance,
the nous or Reason. This is a duality, constituting Being and Knowl-
edge. Thus Thought and Being hold a second place in the universe.
In a similar way from Reason proceeds the third h3^ostasis or the
World-Soul. This stands midway between the intelligible world, of
which it is the last, and the phenomenal world, of which it is the first.
The Soul has a dual aspect, the one spiritual and pertaining to the
intelligible world, the other, called Nature, residing in the lower world.
This is the material world of change and decay. Matter is responsible
for all change and evil, and yet matter, too, is a product of the powers
above it, and is ultimately a derivative of the Absolute Cause, though
indirectly. Matter is two-fold, intelligible and sensible. The matter of
the lower world is the non-existent and the cause of evil. Matter in a
more general sense is the indeterminate, the indefinite and the poten-
tial. Matter of this nature is found also in the intelligible world. The
Reason as the second hj^ostasis, being an activity, passes from
potentiality to actuality, its indeterminateness being made determin-
ate by the One or the Good. This potentiality and indeterminateness
is matter, but it is not to be confused with the other matter of the phe-
nomenal world.
Man partakes of the intelligible, as well as of the sensible world.His body is material, and in so far forth partakes of the evil of matter.
But his soul is derived from the universal soul, and if it conducts itself
properly in this world, whither it came from without, and holds itself
aloof from bodily contamination, it will return to the intelligible world
where is its home.
We see here a number of ideas foreign to Aristotle, which are foundfirst in Philo the Jew and appear later in mediaeval philosophy. Thus
God as a Being absolutely unknowable, of whom negations alone aretrue just because he is the acme of perfection and bears no analogy to
the imperfect things of our world; matter in our world as the origin
of evil, and the existence of matter in the intelligible worldall these
INTRODUCTION xxxix
ideas will meet us again in Ibn Gabirol, in Ibn Daud, in Mainionides,
some in one, some in the other.
Alike in respect to Aristotle as in reference to Plotinus, the Jewish
philosophers found their models in Islamic writers. The "Theology of
Aristotle" which, as we have seen, is really Plotinian rather than
Aristotelian, was translated into Arabic in the ninth century and
exerted its influence on the Brethren of Purity, a Mohammedan secretorder of the tenth century. These men composed an encyclopaedia of
fifty-one treatises in which is combined Aristotelian logic and physics
with Neo-Platonic metaphysics and theology. In turn such Jewish
writers as Ibn Gabirol, Bahya, Ibn Zaddik, Judah Halevi, Moses and
Abraham Ibn Ezra, were much indebted to the Brethren of Purity.
This represents the Neo-Platonic influence in Jewish philosophy.
The Arab Aristotelians, Al Kindi, Al Farabi, Avicenna and Averroes,
while in the main disciples of the Stagirite, were none the less unable
to steer clear of Neo-Platonic coloring of their master's doctrine, and
they were the teachers of the Jewish AristoteUans, Abraham Ibn
Daud, Moses ben Maimon, Levi ben Gerson.
One other phase must be mentioned to complete the parallelism of
Islamic and Jewish philosophy, and that is the anti-philosophic
attitude adopted by Judah Halevi and Hasdai Crescas. It was not a
dogmatic and unreasoned opposition based simply upon the un-
Jewish source of the doctrines in question and their incompatibility
with Jewish behef and tradition, such as exhibited itself in the con-
troversies that raged around the "Guide" of Maimonides. Here we
have rather a fighting of the philosophers with their own weapons.
Especially do we find this to be the case in Crescas who opposes
Aristotle on philosophic grounds. In Judah Halevi similarly, though
with less rigor and Httle technical discussion, we have nevertheless a
man trained in philosophic hterature, who found the philosophicattitude unsympathetic and unsatisfying because cold and impersonal,
faihng to do justice to the warm yearning after God of the rehgioussoul. He could not abide the philosophic exclusion from their naturaltheology of all that was racial and national and historic in religion,
which was to him its very heart and innermost essence.
In this attitude, too, we find an Arab prototype in the person of Al
Gazali, who similarly attacked the philosophers on their own ground
xl INTRODUCTION
and found his consolation in the asceticism and mysticism of the
Sufis.
We have now spoken in a general way of the principal motives ofmediaeval Jewish philosophy, of the chief sources, philosophical and
dogmatic, and have classified the Jewish thinkers accordingly as
Mutakallimun, Neo-Platonists and Aristotelians. We also sketchedbriefly the schools of philosophy which influenced the Jewish writers
and determined their point of view as Kalamistic, Neo-Platonic or
AristoteUan. There still remains as the concluding part of the in-
troductory chapter, and before we take up the detailed exposition of
the individual philosophers, to give a brief and compendious char-
acterization of the content of mediaeval Jewish philosophy. We shallstart with the theory of knowledge.
We have already referred to the attitude generally adopted by themediaeval Jewish thinkers on the relation between rehgion and philos-
ophy. With the exception of Judah Halevi and Hasdai Crescas the
commonly accepted view was that philosophy and religion were at
bottom identical in content, though their methods were different;
philosophy taught by means of rational demonstration, religion by
dogmatic assertion based upon divine revelation. So far as the actual
philosophical views of an Aristotle were concerned, they might be
erroneous in some of their details, as was indeed the case in respect to
the origin of the world and the question of Providence. But apart
from his errors he was an important guide, and philosophy generally is
an indispensable adjunct to rehgious behef because it makes the latter
intelligent. It explains the why's and the wherefore's of religious
traditions and dogmas. Into detailed discussions concerning the
origin of our knowledge they did not as a rule go. These strictly
scientific questions did not concern, except in a very general way, the
main object of their philosophizing, which was to gain true knowledge
of God and his attributes and his relation to man. Accordingly we
find for the most part a simple classification of the sources of knowl-
edge or truth as consisting of the senses and the reason. The latter
contains some truths which may be called innate or immediate, suchas require no experience for their recognition, like the logical laws of
thought, and truths which are the result of inference from a fact of
sensation or an immediate truth of the mind. To these human sources
INTRODUCTION xli
was added tradition or the testimony of the revealed word of God in
the written and oral law.
When Aristotle began to be studied in his larger treatises and thedetails of the psychology and the metaphysics became known espe-
cially through Averroes, we find among the Jews also an interest in the
finer points of the problem of knowledge. The motives of Plato's
idealism and Aristotle's conceptualism (if this inexact description maybe allowed for want of a more precise term) are discussed with fulness
and detail by Levi ben Gerson. He realizes the difficulty involved inthe problem. Knowledge must be of the real and the permanent.
But the particular is not permanent, and the universal, which is
permanent, is not real. Hence either there is no knowledge or there is a
reality corresponding to the universal concept. This latter was the
view adopted by Plato. Gersonides finds the reality in the thoughts of
the Active Intellect, agreeing in this with the views of Philo and
Augustine, substituting only the Active Intellect for their Logos.
Maimonides does not discuss the question, but it is clear from a casual
statement that like Aristotle he does not believe in the independent
reahty of the universal (Guide III, i8).
In theoretical physics the Arabian Mutakallimun, we have seen
(p.xxii), laid great stress on the theory of atom and accident as opposed
to the concepts of matter and form by which Aristotle was led to
believe in the eternity of the world. Accordingly every Mutakallim
laid down his physical theory and based on it his proof of creation.
This method was followed also by the early Jewish thinkers. The
Karaites before Maimonides adopted the atomic theory without
question. And Aaron ben Elijah, who had Maimonides's "Guide"
before him, was nevertheless sufficiently loyal to his Karaite predeces-
sors to discuss their views side by side with those of the Aristotelians
and to defend them against the strictures of Maimonides. Saadia,
the first Rabbanite philosopher, discusses no less than thirteen er-
roneous views concerning the origin and nature of the world, but he
does not lay down any principles of theoretical physics explicitly.
He does not seem to favor the atomic theory, but he devotes no specialtreatment to the subject, and in his arguments for creation as opposed
to eternity he makes use of the Kalamistic concepts of substance
and accident and composition and division. The same is true of
xlii INTRODUCTION
Bahya Ibn Pakuda. Joseph Ibn Zaddik is the first who finds it neces-
sary to give an independent treatment of the sciences before proceed-
ing to construct his rehgious philosophy, and in so doing he expounds
the concepts of matter and form, substance and accident, genesis and
destruction, the four elements and their natures and so onall theseAristotelian concepts. Ibn Daud follows in the path of Ibn Zaddik
and discusses the relevant concepts of potentiaHty and actuality and
the nature of motion and infinity, upon which his proof is based of
the existence of God. Maimonides clears the ground first by a thor-
ough criticism and refutation of the Kalamistic physics, but he does
not think it necessary to expound the Aristotelian views which he
adopts. He refers the reader to the original sources in the Physics
and Metaphysics of Aristotle, and contents himself with giving a list
of principles which he regards as estabHshed. Aristotle is now the
master of all those who know. And he reigns supreme for over a
century until the appearance of the Or Adonai" of Hasdai Crescas,
who ventured to deny some of the propositions upon which Maimon-
ides based his proof of the existence of Godsuch, for example, asthe impossibility of an infinite magnitude, the non-existence of an
infinite fulness or vacuum outside of the limits of our world, the
finiteness of our world and its unity, and so on.
These discussions of the fundamental principles of physics were
applied ultimately to prove the existence of God. But there was a
difference in the manner of the application. During the earlier period
before the "Emunah Ramah" of Abraham Ibn Daud was written,
the method employed was that of the Arabian Mutakallimun. That
is, the principles of physics were used to prove the creation of the
world in time, and from creation inference was made to the existence
of a Creator, since nothing can create itseK. The creation itself in
time as opposed to eternity was proved from the fact of the composite
character of the world. Composition, it was said, implies the prior
existence of the constituent elements, and the elements cannot be
eternal, for an infinite past time is unthinkable. This method is
common to Saadia, Bahya, Joseph Ibn Zaddik, and others.
With the appearance of Ibn Daud's masterpiece, which exhibits
a more direct familiarity with the fundamental ideas of Aristotle,
the method changed. The existence of God is proved directly from
INTRODUCTION xliii
physics without the mediation of the doctrine of creation. Motion
proves a mover, and to avoid an infinite regress we must posit an
unmoved mover, that is, a first mover who is not himself moved at
the same time. An unmoved mover cannot be corporeal, hence he
is the spiritual being whom we call God. Ibn Daud does not make
use of creation to prove the existence of God, but neither does he
posit eternal motion as Aristotle does. And the result is that he has
no vaHd proof that this unmoved mover is a pure spirit not in any
way related to body. This defect was made good by Maimonides.
Let us frankly adopt tentatively, he says, the Aristotehan idea of the
eternity of the world, i. e., the eternity of matter and motion. We canthen prove the existence of an unmoved mover who is pure spirit,
for none but a pure spirit can have an infinite force such as is mani-
fested in the eternal motion of the world. Creation cannot be demon-
strated with scientific rigor, hence it is not safe to build so important
a structure as the existence of God upon an insecure foundation.
Show that eternity of the world leads to God, and you are safe no
matter what the ultimate truth turns out to be concerning the origin
of the world. For if the world originated in time there is no doubt
that God made it.
Thus Maimonides accepted provisionally the eternity of matter
and motion, but provisionally only. No sooner did he prove his point,than he takes up the question of the world's origin and argues that
while strict demonstration there is as yet none either for or against
creation, the better reasons are on the side of creation.
Gersonides, on the other hand, was a truer Aristotelian than Mai-
monides and he decided in favor of the eternity of matter, though
not of this our world.
The Jewish Mutakallimun, as we have seen, proved the existence of
God from the fact that a created world impUes a creator. The next
step was to show that there is only one God, and that this one God is
simple and not composite, and that he is incorporeal. The unity in
the sense of uniqueness was shown by pointing out that dualism or
pluralism is incompatible with omnipotence and perfectionattri-butes the possession of which by God was not considered to require